DESCRIPTION: Dental adhesives have major limitations, including: inadequate bond strength to dentin to overcome forces generated by contraction of the composite restorative; gap formation that leads to bacterial penetration and staining at the margins with the tooth surface; and limited durability due to polymer degradation and a limitation of the joint from water sorption and stressing during clinical service. These limitations create problems for the patient, including post-operative tooth pain, deterioration of the health of the tooth, and the need for costly re-treatment. This project seeks to develop materials that can produce reliable and durable bonds to tooth surfaces. This material will be capable of "self-healing" the interfacial porosity that forms immediately after placement and during clinical service, due to the development of a biomimetic approach. In addition, this material is expected to be useful as an adhesive for all hard tissues in the body. This work has two long-range goals: 1) Prepare novel, hard tissue adhesive biomaterials with the capacity for self-healing; and 2) identify the mechanism of adhesion and sealing through physical and chemical characterization of the interface between this biomaterial and hard tissues. The main objective is to create a biomimetic process to: 1) Eliminate the formation of nano- and micro-scale leakage at the tooth/adhesive interface; and 2) improve the bond strength between a Dental adhesive material and tooth structure. We will prepare a series of bioactive sol gel glass-containing Dental adhesives, and assess their physical, chemical, and mechanical properties, identifying those compositional factors, structural properties, and placement methods that will improve the seal and bond between the Dental adhesive and the tooth. Additionally we will characterize the changes in the interface between tooth and restoration.